Slow draining lav without overflow

We used your site extensively during construction of our house and found it MOST helpful!

I think I recall some information or discussion about bathroom sinks without an overflow drain on this website. We have 3 of the obnoxious fixtures. Do you have suggestions on how to get them to drain, besides sticking a drinking straw into the drain to let the air out? I seem to recall someone saying there is a device that can be attached below the sink to basically act as an air escape (like an overflow). Can you give us any helpful information to correct this situation?